The best way to save money is to stick with in-state tuition. The least cost in-state tuition is usually starting at community college.
Study abroad credits (with a school-sponsored program) are not considered transfer credits. They are the same as being taught on campus as far as meeting graduation requirements is concerned.
If you do look out of state, look at schools that offer big scholarships. If won’t be popular schools like UVA or Michigan. There’s a thread on the financial aid board that collects merit scholarships.